During the first year of the project over 30 new steroids derivatives have been synthesized and labeled with fluorescent agents. In a preliminary trial, strong correlation of in vitro and in vivo uptake properties of these compounds and cell free receptor assays was obtained. Initial structural characterization of the fluorescent steroids has been completed and definitive structural analysis is underway. Initial examination of histochemical methods for detecting steroid receptors reported by others has been completed. During the second year of the project further structural verification of the fluorescent steroids and careful histological, biochemical and clinical correlation of the methods is planned.